The present invention to aircraft and provides an envelope which is foldable during nonuse for an air balloon and airship.
A conventional envelope of the airship was extended on the ground, sent a hot air into the envelope by using a burner and inflated to the envelope during use, and can be folded during a time of nonuse by a hand and could be put away.
The conventional envelope requires a lot of time and effort to take out of the envelope from the gondola or envelope storage bag, extend it on the ground, and inflate and fold to the envelope. Moreover, the folded envelope have to be storaged into the gondola or envelope storage bag.